Methods and Devices for Paranasal Sinus Drug Delivery

ABSTRACT

Described herein are methods and devices for delivering a drug to the frontal sinus system. An inflatable implant is positioned within the frontal sinus system using an anchoring means secured within the frontal sinus cavity. A drug-containing fluid is released directly into the frontal sinus drainage system.

RELATED APPLICATION

This application claims priority to U.S. Provisional Patent ApplicationNo. 61/172,426 filed on Apr. 24, 2009, which is incorporated byreference as if set forth fully herein.

FIELD OF THE INVENTION

The field of the invention generally relates to medical devices andmethods of treating the sinus system of a mammal such as a human.

BACKGROUND

Interest continues to increase in the potential for site-specific drugdelivery in the sinuses and sinus drainage pathways. Once such device isdescribed in U.S. Pat. No. 7,419,497. In one embodiment, '497 teaches aballoon that is placed in situ, filled with a drug-containing material(e.g., a steroid cream), and left in place for an extended period oftime (e.g., 2 weeks). The '497 balloon has weep holes which allow thedrug-containing material to ooze out over time.

SUMMARY OF THE INVENTION

This invention is directed towards devices and methods of use relatingto implanting a fluid-dispensing implant within the frontal sinus systemof a human.

In some embodiments, the invention includes a method of delivering afluid to the frontal sinus system of a mammal, the method comprisingdirecting an implant into a frontal sinus system of the mammal. Theimplant can include at least one fluid reservoir, at least one anchoringstructure, and at least one dispensing structure. The dispensingstructure can be in fluid communication with the fluid reservoir. Theimplant can be positioned so that the anchoring structure is locatedwithin a frontal sinus cavity of the frontal sinus system and most orall of the dispensing structure is located within the frontal sinusdrainage pathway. A fluid can be directed from the fluid reservoirthrough the dispensing structure, thereby delivering the fluid to thefrontal sinus system of the mammal over a period of time of at least aday. In this way, at least a portion of the fluid enters the frontalsinus drainage pathway directly from the dispensing structure. In someembodiments, the entire dispensing structure is located within thefrontal sinus drainage pathway so that all or substantially all of thefluid enters the frontal sinus drainage pathway directly from thedispensing structure.

In some embodiments, the fluid reservoir is an inflatable structure(e.g., a balloon) while in other embodiments the fluid reservoir is arigid container. The dispensing structure can be, for example, aplurality of holes disposed within an outer surface of the inflatablestructure and/or disposed within an outer surface of a tube connected tothe fluid reservoir. The holes can be in fluid communication with aninterior portion of the balloon. In some embodiments, the fluidreservoir is an inflatable structure and can be expanded by directingthe fluid to an interior portion of the inflatable structure. In someembodiments, most or all of the fluid reservoir is positioned within thefrontal sinus drainage pathway, while in other embodiments most or allof the fluid reservoir is positioned within the frontal sinus cavity.

In some embodiments, the invention includes a method of delivering afluid to the frontal sinus system of a mammal. The method includesdirecting an implant into a frontal sinus system of a mammal, theimplant including at least one inflatable structure, one anchoringstructure, and one dispensing structure. The anchoring structure isdirected into a frontal sinus cavity of the frontal sinus system. Thedispensing structure is directed into a portion of a frontal sinusdrainage pathway in fluid communication with the sinus cavity. Theanchoring structure is secured within a frontal sinus cavity of thefrontal sinus system. The inflatable structure is expanded by directinga fluid into the inflatable structure. The fluid is dispensed directlyinto the frontal sinus drainage pathway from the dispensing structure,the fluid being delivered over a period of time of at least a day (e.g.,one day, two days, three days, a week, two weeks, a month, or severalmonths). The dispensing structure can be a plurality of holes in theinflatable structure or a plurality of holes that are situated on theouter surface of a hollow lumen that is in fluid communication with theinflatable structure. In some embodiments, the inflatable structure ispositioned within the frontal sinus cavity while in other embodiments itis positioned within the frontal sinus drainage pathway.

In some embodiments, to ease insertion into the anatomy, the anchoringstructure, the inflatable structure, or both are secured in a hollowlumen when the implant is directed into the frontal sinus system. Insome embodiments, the inflatable structure is a non-cylindrical balloon(e.g., a lobed balloon).

The fluid used in the method can include a pharmaceutical agent. Theinflatable structure can be “recharged” by directing another portion offluid into the inflatable structure after the initial fluid-dispensinginterval period of time.

In further embodiments, the method includes directing an implant into afrontal sinus system of a mammal, the implant including at least oneinflatable structure and one anchoring structure, the anchoringstructure being secured to a distal portion of the implant and theinflatable structure being positioned proximal relative to the anchoringstructure. The anchoring structure can be directed into a frontal sinuscavity of the frontal sinus system and the inflatable structure can bedirected into a portion of the frontal sinus drainage pathway. A fluidcan be directed into the inflatable structure, the fluid comprising adrug. The fluid is directed into the frontal sinus drainage pathway fromholes in the outer surface of the inflatable structure, the fluid beingdelivered over a period of time of at least a day (e.g., one day, twodays, three days, a week, two weeks, a month, or several months).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a schematic representation of an embodiment of thepresent invention that includes a distal portion of a catheter.

FIG. 2 illustrates a schematic representation of an embodiment of thepresent invention that includes a catheter.

FIG. 3 illustrates a portion of the catheter of FIGS. 1 and 2 installedwithin the frontal sinus and frontal sinus drainage pathway.

FIG. 4 illustrates a schematic representation of an embodiment of thepresent invention that includes a distal portion of a catheter.

FIG. 5 illustrates a schematic representation of an embodiment of thepresent invention that includes a catheter.

FIG. 6 illustrates a schematic representation of an embodiment of thepresent invention that includes a lobed balloon.

FIG. 7 illustrates a schematic representation of an embodiment of thepresent invention that includes a distal portion of a catheter.

FIG. 8 illustrates a schematic representation of a side view of one halfof a typical frontal sinus system.

DETAILED DESCRIPTION

Historically, there has been some amount of confusion in the anatomicalnomenclature of the human sinus system because the sinus system isfairly complicated and can vary between individuals. The frontal sinussystem in particular has a complex and variable drainage system,compared to the other paranasal sinuses. As used herein, the “frontalsinus system” includes the frontal sinus cavities and the frontal sinusdrainage pathway (further described below).

FIG. 8 illustrates a schematic representation of a side view of one halfof a typical frontal sinus system. The general drainage flow pathway ofthe frontal sinus system is illustrated as arrow 801, which extends fromthe frontal sinus cavity 802 and drains into the nasal cavity. Thefrontal sinus cavity 802 is located behind the supercilliary arch 804.The cavity 802 typically narrows down to an inferior margin called thefrontal ostium 806 which extends between the anterior and posteriorwalls of the frontal sinus 802. The frontal ostium 806 is demarcated bya shaped ridge of bone on the anterior wall of the sinus and is orientednearly perpendicular to the posterior wall of the sinus.

The frontal sinus drainage pathway has a superior and inferior componentindicated generally as 808 and 810, respectively. The superior component808 is formed by the union of adjacent air spaces at the anterioinferiorportion of the frontal bone and the anteriosuperior portion of theethmoid bone, its upper border being the frontal ostium 806. Thesuperior component 808 is in direct fluid communication with theinferior component 810. The inferior component 810 is a narrowpassageway typically formed by ethmoid air cells, such as the agger nasi820 and ethmoid bulla 822, and may further include the ethmoidinfundibulum 824. When the anterior portion of the uncinate process 812extends superiorly to attach to the skull base (not illustrated), theinferior compartment 810 includes the ethmoid infundibulum 824. When theanterior portion of the uncinate process 812 extends superiorly toattach to the skull base (not illustrated), the inferior compartment 810includes the ethmoid infundibulum 824. When the anterior portion of theuncinate process 812 is attached to the lamina papyracea instead of theskull base (not illustrated), the inferior compartment 810 is then themiddle meatus (not illustrated). As used herein, the “frontal sinusdrainage pathway” or “frontal sinus drainage system” is defined as thecombination of the superior component 808 and inferior component 810 andis demarcated by the frontal ostium 806 and inferiorly by the floor ofthe inferior component.

FIGS. 1 and 2 illustrate an embodiment of the present invention, whichincludes the distal portion 100 of catheter 126. The Balloon catheterincludes a fluid reservoir in the form of membrane or balloon portion102. Distal portion 100 includes an anchoring structure in the form oftwo retention members or wings 104 attached or extending distally fromdistal tip 116 of balloon portion 102. Because wings 104 are positioneddistally from balloon portion 102, distal portion 100 can be positionedin the drainage pathway of a frontal sinus (rather than in the sinuscavity itself) while wings 104 are extended or deployed within the sinuscavity to maintain the position of the implant.

Balloon portion 102 includes a dispensing structure in the form of aseries of transport passage or ports 106 that allow a fluid material(e.g., a drug-containing material or agent, such as an anti-scarring ortissue proliferation agent) to weep out of balloon portion 102 onceimplanted into a sinus drainage pathway. Most or all of balloon portion102 is placed within the drainage pathway itself, which allows the drugto be more effectively delivered to this region as compared to a devicethat releases a drug-containing material within the sinus cavity. Forexample, distal portion 100 can be placed within a frontal drainagepathway to prevent scarring or closure of the frontal recess via acombination of pharmaceutical activity from the wept material as well asthe physical blockage represented by the presence of balloon portion 102itself.

Distal portion 100 includes valve member 108 which acts as a one-wayvalve to allow for filling of balloon portion 102 with a material alongpath 110 which flows through catheter shaft 112 and out into an interiorof balloon portion 102 via port 114. Valve member 108 is preferablycircular, with a hole in the center. Under pressure, the fluid materialdeflects the valve member 108 and passes distally or antegrade into thebody of balloon portion 102. After pressure is released, valve member108 resumes its relaxed shape and closes off the hole in its center,thereby preventing retrograde flow through shaft 112. The fluid materialweeps out of balloon portion 102 along or parallel to paths 118 viaports 106 to dispense the material in situ.

FIG. 2 illustrates most of the length of catheter 126. Sheath 120 isdisposed along a length of shaft 112 of catheter 126. In use, sheath 120is initially positioned to cover collapsed balloon portion 102 a and allor most of retention wings 104. Once positioned in a desired location(e.g., with balloon portion 124 and wings 104 in the frontal drainagepathway and frontal sinus, respectively), sheath 120 is pulled backalong shaft 112 to allow wings 104 to expand radially outward relativeto the central axis of shaft 112 and sufficiently enough to removeballoon portion 102 from the lumen of sheath 120. In this manner, theouter diameter of the anchoring structure (e.g., retention wings 104) isexpanded within the frontal sinus cavity as illustrated, for instance,in FIG. 3. Then balloon portion 102 is inflated with air or a fluid(e.g., a drug-containing fluid) to form inflated balloon portion 102 b.In some embodiments, insertion of catheter 126 and positioning ofballoon portion 102 is facilitated by a guide catheter (notillustrated). In other embodiments, catheter 126 is inserted by directplacement, preferably under endoscopic visualization. In yet furtherembodiments, the catheter shaft or portions thereof are curved tofacilitate placement within the human anatomy.

FIG. 3 illustrates a portion of catheter 126 installed within thefrontal sinus and frontal drainage pathway. Specifically, wings 104 havebeen deployed within the frontal sinus cavity and inflated balloonportion 102 b is located within the frontal drainage pathway. Oncepositioned and filled, most of shaft 112 is cut away from inflatedballoon portion 102 b, leaving behind portion of shaft 126. The proximalcut end of portion of shaft 126 can be further secured to the nasalmucosa with a suture or other suitable means. Alternatively, once shaft112 is cut, the cut end of portion of shaft 126 can be directed or“tucked away” into the maxillary ostium or behind the uncinate processso as to be completely out of the breathing space of the nasal passages.After an appropriate amount of time (e.g., ˜2 weeks in the case ofdelivering a steroid compound), the implanted portions of the device canbe removed by gentle traction. The desired length of in situ time willbe a function of the drug used, the amount of time it takes for thedrug-containing material to weep out of the device, and/or surgeonpreference.

FIGS. 4 and 5 illustrate another embodiment of the invention thatincludes catheter 400. Illustrated in FIG. 4, distal portion 402 ofcatheter 400 includes a fluid reservoir in the form of balloon portion404 and an anchoring structure in the form of retention wings 406.Retention wings 406 are secured to the distal tip of core 408. Core 408is slidably arranged within the lumen of shaft 410. Core 408 can moverelative to shaft 410 along direction 412. In some embodiments, core 408is frictionally engaged with some other portion of catheter 400 toprovide an amount of resistance between the relative movement betweencore 408 and shaft 410. For example, in some embodiments, tip 414 ofcatheter 402 creates a frictional engagement with core 408.Alternatively, or in addition, valve member 416 can create a frictionalengagement with core 408.

FIG. 5 illustrates a part of the deployment process for catheter 400.Prior to implantation, catheter 400 is arranged such that collapsedballoon portion 404 a and retention wings 406 are located within adistal portion of sheath 418. Once directed to a desirable locationwithin the frontal sinus system, sheath 418 is pulled proximally backrelative to shaft 410 in a direction roughly parallel to arrow 412,thereby releasing retention wings 406 and removing collapsed balloonportion 404 a from the lumen of sheath 418. Retention wings 406 can bedeployed, for example, within a frontal sinus cavity.

Once retention wings 406 are deployed, core 408 can be moved relative toshaft 410 by applying a force sufficient to overcome the frictionalengagement between core 408 and tip 414, valve member 416 and/orwhatever other frictional engagement means are employed. In this manner,the relative distance between collapsed balloon 404 a and retentionwings 406 can be varied, thereby allowing a practitioner of thisinvention to place collapsed balloon 404 a in a desirable location(e.g., within the frontal drainage pathway). Once positioned, collapsedballoon 404 a is inflated or filled with a fluid material (e.g., adrug-containing material) to form inflated balloon 404 b. Afterinflation, shaft 410 can be cut away and, optionally, whatever portionof the shaft that is not cut away from inflated balloon 404 b can besecured to the nasal mucosa.

In some embodiments, the balloon portion is made to take some form ofnon-cylindrical shape when inflated with the fluid material. FIG. 6illustrates one such embodiment where balloon 602 has, when inflated, aseries of three “lobes” 606. Each lobe 606 is formed between two ofpoints 604 which indicate places where the balloon membrane is attachedor secured to shaft 608. When the fluid medium is directed into theballoon 602, it inflates and the three lobes 606 form a clover-likeshape. A lobed-shaped balloon can be beneficial in that it will be lesslikely to obstruct the entire natural drainage pathway of a frontalsinus. While FIG. 6 illustrates an embodiment having three lobes, otherembodiments of this invention includes balloons with 2, 4, or more than4 lobes. A lobed-shaped balloon may be incorporated into any of theother embodiments described herein.

In further embodiments of the invention, the dispensing structure takesthe form of transport passages or ports, through which a drug-containingfluid can weep or otherwise be dispensed into the anatomy, that arelocated in a portion of the shaft. FIG. 7 illustrates one suchembodiment. Distal portion of catheter 700 includes a fluid reservoirstructure in the form of balloon portion 702 attached to the distal endof a hollow shaft forming outer tube 704. Inner tube 706 is disposedwithin the lumen of outer tube 704. Inner tube 706 extends through outertube 704 and balloon portion 702.

Cap 708 is disposed on the distal end of inner tube 706. Valve member710 is disposed within the lumen of inner tube 706 and includes flowport 712. The lumen of inner tube 706 is in fluid communication with theinterior of balloon portion 702 via port 712. The diameters of at leasta portion of the distal ends of inner and outer tubes 706, 704 aredissimilar such that there is a small space or gap 714 therebetween. Thedistal end portion of outer tube 704 includes a dispensing structure inthe form of a series of flow ports 716 in fluid communication with gap714, interior of balloon portion 702 and the lumen of inner tube 706. Ananchoring structure in the form of retention wings 718 are attached orsecured to outer tube 704 at a location proximal relative to balloonportion 702. Sealing means 740 (e.g., a rubber washer or other plug) ispositioned within gap 714 between inner and outer tubes 706, 704.

The embodiment illustrated in FIG. 7 can be implanted much the same wayas the other embodiments illustrated herein, one of the main differencesbeing that both balloon portion 702 and retention wings 718 can beplaced within the frontal sinus cavity while a portion of inner andouter tubes 706, 704 extend down into the frontal sinus drainagepathway. Flow ports 716 in outer tube 704 will discharge or weep thefluid material directly into the drainage pathway while in the sinuscavity i) retention wings 718 secure the implant and ii) balloon portion702 stores a supply of the fluid material. In this way, balloon portion702 can be larger and store more fluid material relative to anembodiment where the balloon portion is positioned within the drainagepathway.

The embodiment described in FIG. 7 can be implanted using a sheath,similar to what was described above. Specifically, some or all of distalportion 700 can be contained within the lumen of a sheath, withun-deployed retention wings 718 and collapsed balloon portion 702 foldedto a profile having a relatively small diameter. When directed to thedesired position, the sheath can be slid proximally relative to outerand inner tube 704, 706, thereby allowing retention wings 718 to extendradially outward and, if the sheath contained balloon portion 702, andremoving balloon portion 702 from the lumen of the sheath. Once distalportion 700 is in the desired location and the sheath (not illustratedin FIG. 7) has been slid back to release balloon portion 702 andretention wings 718, a fluid material (e.g., a drug-containing material)is directed up the lumen of inner tube 706 along direction 720, throughvalve member 710, and into the interior portion of balloon portion 702,thereby inflating balloon portion 702. Inner tube 706 is cut at aposition (e.g., a position proximal relative to sealing means 720) thatresults in the desired length of its distal portion within the drainagepathway. In situ, fluid material flows from the interior of balloonportion 702 down through gap 714 and out ports 716 along direction 722.

In some embodiments, the balloon portion of the implant can be“recharged” one or more times with additional fluid material by, forexample, delivering a fresh supply of the same or different fluid to theballoon portion with a syringe and needle. In this way, the inventioncan be used to administer a fluid to the sinus drainage pathway for alonger period of time.

Various modifications of the devices and methods described herein can becontemplated by those of skill in the art and are within the scope ofthis invention. Various specific dimensions and materials of thecomponents of the device embodiments contemplated by those of skill inthe art are also within the scope of the invention.

1. A drug delivery system, comprising: an elongated shaft comprising anouter tube and an inner tube, wherein the inner tube is disposed in afirst lumen of the outer tube, wherein the inner tube defines a secondlumen; a fluid reservoir in fluid communication with the inner tube viaa flow port in the inner tube, wherein the fluid reservoir is further influid communication with the first lumen of the outer tube via a gapbetween the inner tube and the outer tube; and a dispensing structure onthe outer tube, wherein the dispensing structure is configured todispense a fluid to a drainage pathway of a frontal sinus cavity; and ananchoring structure configured to engage the frontal sinus cavity suchthat the dispensing structure is located in the drainage pathway of thefrontal sinus cavity, wherein the inner tube, the fluid reservoir, theouter tube, and the dispensing structure define a fluid pathway suchthat the fluid flows (i) distally along the second lumen of the innertube, (ii) from the second lumen of the inner tube to the fluidreservoir via the flow port, (iii) from the fluid reservoir to the firstlumen of the outer tube via the gap between the inner tube and the outertube, (iv) proximally along the first lumen of the outer tube to thedispensing structure, and (v) through the dispensing structure to thedrainage pathway of the frontal sinus cavity.
 2. The drug deliverysystem of claim 1, wherein the fluid reservoir has a proximal end and adistal end, wherein the inner tube extends through the proximal end ofthe fluid reservoir to the distal end of the fluid reservoir.
 3. Thedrug delivery system of claim 2, the proximal end of the fluid reservoiris coupled to outer tube.
 4. The drug delivery system of claim 3, thedistal end of the fluid reservoir is coupled to inner tube.
 5. The drugdelivery system of claim 2, wherein the fluid reservoir is an inflatableballoon.
 6. The drug delivery system of claim 5, wherein the inflatableballoon comprises a plurality of lobes.
 7. The drug delivery system ofclaim 2, wherein the fluid reservoir is a rigid container.
 8. The drugdelivery system of claim 1, further comprising a one-way valve in thesecond lumen of the inner tube, wherein the one-way valve is locatedproximal of the flow port.
 9. The drug delivery system of claim 1,wherein the dispensing structure comprises a plurality of ports alongthe outer tube.
 10. The drug delivery system of claim 9, wherein theplurality of ports along the outer tube are disposed along a centralaxis of the elongated shaft, wherein the central axis is in a directionbetween a proximal end of the elongated shaft and a distal end of theelongated shaft.
 11. The drug delivery system of claim 1, furthercomprising a cap at a distal end of the inner tube, wherein the cap isconfigured to assist in directing the fluid from the second lumen of theinner tube to the flow port.
 12. The drug delivery system of claim 1,wherein the outer tube is sealed to the inner tube a location that isproximal of the dispensing structure.
 13. The drug delivery system ofclaim 12, further comprising a washer positioned between the inner tubeand the outer tube at the location that is proximal of the dispensingstructure, and wherein the washer is configured to seal the outer tubeto the inner tube.
 14. The drug delivery system of claim 1, wherein theanchoring structure coupled to the elongated shaft at a location that isproximal of the fluid reservoir.
 15. The drug delivery system of claim14, wherein the anchoring structure comprises plurality of retentionwings.
 16. The drug delivery system of claim 15, wherein an outerdiameter of the plurality of the anchor structure is configured toexpand, relative to a central axis of the elongated shaft, from a firstdiameter to a second diameter.
 17. The drug delivery system of claim 1,wherein the fluid comprise a pharmaceutical agent.
 18. The drug deliverysystem of claim 1, further comprising a sheath comprising a third lumen,wherein at least a portion of the elongated shaft is disposed in thethird lumen of the sheath, wherein the sheath is movable between adistal position on the elongated shaft and a proximal position on theelongated shaft, and wherein the anchor structure is contained withinthe third lumen of the sheath when the sheath is in the distal position.19. The drug delivery system of claim 18, wherein the anchor structureis expandable responsive to the sheath moving from the distal positionto the proximal position.
 20. The drug delivery system of claim 18,wherein the fluid reservoir is contained within the third lumen of thesheath when the sheath is in the distal position, and the fluidreservoir is configured to expand when the sheath is in the proximalposition.